New genetic technologies combined with a well characterize genome make the mouse the preferred mammalian model for human disease. Investigators must be able to characterize them genetically and physiologically to exploit their full biomedical potential. To realize this potential, investigators must measure the same basic clinical chemistry parameters used in human diagnostic medicine. The staff of The Jackson Laboratory (TJL) is at the forefront both in defining the normative biology of standard inbred mice and in characterizing hundreds of new mutations of biomedical significance. Clinical laboratory determinations are essential for phenotypical characterization of the many new inbred strains and congenic lines developed by TJL Staff, and many new spontaneous and induced mutations. No such instrumentation currently exists at TJL. An automated clinical chemistry analyzer, the Synchron Cx5 Delta, Beckman Instruments, Brea, CA, has proven its reliability in human diagnostic medicine. Because it requires only small volumes of serum, plasma, or urine, this analyzer would meet the needs of TJL staff for measurement of a variety of common biochemical analytes in these biological fluids. The Cx5 Delta represents a cost-efficient mechanism for measuring these relevant physiologic parameters. At TJL more than 86% of research projects focus on the analysis of genetic disease. These include either syndromes caused by single gene mutations or more complex, multifactorial genetic diseases, such as cancer, diabetes, and atherosclerosis. Such studies generate many hundreds of progeny in which continuous variation in a complex trait is observed. Accurate measurement of relevant biochemical sub-phenotypes segregating in these populations is essential. Research progress associated with automated collection of a variety of biochemical parameters would greatly enhance current projects. Funds are requested to purchase the Beckman Synchron Cx5 System, to be operated by the institution's Microchemistry Service on a fee for service basis thus providing a cost-effective way to fill an urgent, and currently unmet need of TJL staff.